Combined dial-speaker arrangement for radio receivers



SQpt 19, 19% K EMDE ETAL zfizggwg COMBINED DIA.LSPEAKER ARRANGEMENT FOR RADIO RECEIVERS Filed; Aug, 8, 1946 KURT EMDE HERBERT/'1. STEGLICH INVENTORS.

THE/R ATTORNEY Patented Sept. 19, 1950 COMBINED DIAL-SPEAKER ARRANGEMENT Fo RADIO RECEIVERS Kurt Emde, Itasca, and Herbert H. Steglich,

Wilmette, Ill., assignors to Zenith Radio Corporation, a corporation of Illinois Application August 8, 1946,-Serial No. 689,098

This invention relates to dials and speaker grilles, and more particularly to dials and speaker grilles for radio receiving apparatus employin manually adjustable tuningvmeans and a loud speaker. I

The principal objects of the invention are to provide a combined dial and speaker opening and to locate the tuning indicator with respect to the. loud speaker so that the tuning dial and speaker openings are associated in the front of the casing of the apparatus in such manner that an appreciably larger speaker may -be used and to so arrange the construction as to render it easily accessible for inspection and adjustment and to arrange the speaker to be mounted in such an ingenous manner that necessary space for the appreciably larger speaker is utilized to best advantage in the casing, whereby the ef ficiency of both the dial and loud speaker is improved. It is also an objectto provide a structure which readily lends itself ,to pleasing design. i

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims The present invention itself, both as to further objects and advantages thereof maybest be understood by reference to the following description taken in connection with accompanying 'drawings in which: 1

Figure 1 is a front elevational view of-a radio 7. receiving set embodying a preferred-form of our improved dial and speaker grille;

Figure 2 is a horizontal sectional view, taken on line 2--,2 of Figure l and showing certain parts cut away to expose construction;-

Figure 3 is a perspective view of a complete radio chassis out of the case, illustrating one preferred arrangement of certain parts;

Figure 4 is a vertical sectional view, taken upon the line 44 of Figure l showing a modification of the construction shown in Figures 1, 2 and 3; and

Figure 5 is a plan View of a fragment of a radio chassis out of the case showing another modification of theconstruction shown in Figures 1 2 and 3 and showing certain parts cut away to expose construction. v

The front elevational view of Figure 1 includes a radio case Ihaving a volume and on-oif switch knob 2 and a manual tuning knob 3. The case I is provided with a lower grille. opening 4 and an upper grille and dial openingi. In the lower grille opening l is speaker grille 4A .which 2 Claims. (01. 250-44) may, for example, be wiren esh, cloth, perforated metal, plastic, or the like. In the upper grille and dial aperturesi are the four dial and speaker louvres 6, I, 8 and 9. The speaker louvres l and B have suitable tuning calibrations Ill marked thereon to form dial scale numbers. Each of the four dial and speaker louvres 6, 1, 8 and 9 is inclined at an angle that may be in the order of to away from the front of the case I, (Figures 2 and 4). Each of these louvres lies in the surface of a truncated cone with the apex in front of the front wall of case I. With a suitable width of the dial scale number the angle should lie Within such a limited range because, if it is too large, the space between the louvres would allow easy passage of small objects, such as the point of a pencil, and consequent harm to the speaker cone. Also, it would, at least from a seated position, be more difficult to read the calibrations on dial and speaker louvres I and 8. If the angle be too small, the easy passage and the desired diffusion of sound Waves would be impaired, and it would be somewhat difficult to read the calibrations from a standing position.

When the dial and speaker louvres are limited to such an angle range they present an ideal surface for the calibrations and easily allow the calibrations to be read by anyone from either a sitting orstanding position.

Supporting the upper part of the dial and speaker louvres 5, I, 8 and 9 are apair of radially disposed support bars H engaging cooperating slots (not shown) on rear of front wall of case I. Support means such as bars H are held in these cooperating slots by any conventional means such as spring steel clips or the like (not shown). A horizontal dividing strip or member l2 formed as an integral part of the front wall of case I and separating openings 4 and 5 serves not only to terminate'the dial and speaker louvres, but to provide, on its rear surface, mounting means (not shown) for ends of dial and speaker louvres identical with those provided on the inside of the case for the pair of support bars The dial and speaker louvres 6, l, 8 and 9 are made, preferably, of clear plastic material to allow the dial pointer l3 to be seen behind the calibrations l0.

A central and symmetrical arrangement of the speaker grille and dial results with such an arrangement. Also, a much larger speaker is provided than could be provided with the conventional arrangement of speaker and tuning dial arranged back of separate openings located near opposite ends of the front of the casing.

Pointer I3 is fixedly attached to a grooved pulley I4 rotatably mounted on a Y-shaped support bracket I5 which is in turn mounted on rim I6 of speaker bell-frame I1 (Figures 2 and 4) of the speaker I8. A second grooved pulley I9 of same diameter as pulley I4 is fixed upon the rotatable shaft 20 of the variable condenser 2|. The variable condenser 2| is secured upon the rightward end part (Figures 1 to 3 inclusive) of the chassis 22 by bolts 23 passed through spacer cushions 24 (Figure 3). A short shaft 25 is rotatably supported in suitable manner upon or within chassis 22 to project forwardly from the front wall thereof through the front of the casing I, and knob 3 is fixed upon the forward endpart of the shaft whereby it may be manually rotated. A cord belt 26 furnishes a connecting drive between shaft 25 and grooved pulley I9, cord belt 26 having its ends jointed together by coiled tension spring 21. A cord belt 28 furnishes a connecting drive between grooved pulley I9 and grooved pulley I4 upon which pointer I3 is mounted. The cord belt 23 has its ends joined together by coiled tension spring 29. An annular portion 36 (Figure 2), on inside surface of the front wall of case I, surrounding apertures 4 and 5, upon which portion the rim ring 3| (Figure 4) of speaker I8 bears, has a cut away portion 32 to allow passage of cord belt 28. In order that this clearance opening be as small as possible, a pair of grooved idler pulleys 33 is employed as hereinafter explained.

In Figure 3 the pair of grooved idler pulleys 33 is pivotally mounted on a shoulder rivet securely staked in the front flap of chassis 22. The lower reachof cord belt 28 bears against the lower rim of one of the pair of idler pulleys and then continues to extend, as the lower reach, over to the pulley I4. The upper reach of cord belt 28 bears against lower rim of the remaining idler pulley of the pair 33 and then continues to extend, as the upper reach, over to pulley I4. By bringing the upper and lower reaches of cord belt 28 to a position approximately in the same plane at the point where they pass through the annular portion 38, a cut away portion 32 of minimum area may be employed, thus cutting down to a minimum, the undesirable diffusion of sound Waves from the speaker I8.

The clearance opening, or cut away portion 32, being open at the edge of the annular portion 33, allows the completed chassis, (Figure 3) with pulleys I4 and I9 completely strung with cord belt 28, to be mounted in case I with a minimum of trouble.

As the pulleys I4 and I9 are of the same size, adjustment of the rotor plates of the 180-degree variable condenser 2| will be correspondingly indicated by the pointer I3 rotating in back of the 180-degree scale calibrations II] on dial and speaker louvres l and 8.

In Figures 3 and 4 the loud speaker is secured upon the forward central portion of the chassis by screws 34 (Figure 4). The top and front vertical wall of chassis 22 forms a recess 35 to receive and support the lower sweep of the bell frame I! and to receive cone 36 of the speaker I3. The screws 31 that mount the Y-shaped bracket I5 to the rim I6 of the speaker I8 also serve to mount the speaker I8 on the recessed flaps 38, 39 of chassis 22. An additional strip 46, formed to follow closely the shape of the recess in the top plate of the chassis 22, is provided to enclose the chassis completely at the area of recessing.

In Figure 4, in which a somewhat different arrangement of dial pointer and drive are shown, many parts are similar to those shown in Figures 1, 2 and 3 and like reference characters are applied thereto.

A dial pointer 4|, having its blade formed in such manner as to lie closely parallel with the dial and speaker louvres 6, I, 8 and 9, is fixedly attached to a grooved pulley 42 rotatably mounted on the rear of the Y-shaped support bracket I5. A dial light 43 mounts on a projecting bracket 44 that projects rearwardly from the Y-shaped support bracket I5. The light shield 45 encompasses the support bracket I5, the grooved pulley 4| and the dial light 42 on three sides.

In mountin the grooved pulley 42 on the rear of the Y-shaped bracket I5 2. means of bringing the cord belt 28 (Figure 3) directly through the diaphragm and over to the grooved pulley l9 must be provided. A pair of grommets 46, which may be of thin rubber construction, metal or pressed paper, are pressed or molded into the paper diaphragm 36. In any event, the holes in the grommets are preferably of sufiicient size and preferably slot shaped, as never to allow the grommets to touch the cord belt 28 even when diaphragm is of large excursion.

The light shield 45, the dial light 43 and. the projecting bracket 44 of Figure 4, although not shown in Figures 1, 2 and 3 may readily be made a part of the construction shown in these figures. Also, the pointer I3 of Figure 3 may, if desired, be used in any form of the invention, although the pointer 4| in Figure 4 has certain advantages for some purposes.

It is a distinct advantage to use the pointer 4| in Figure 4 because visual aberration is reduced to a minimum between the pointer 4| and the sub-divisions (not shown) of calibrations II] on the dial and speaker louvres I and B.

The pointer I3 of Figure 3 is advantageously employed because in this arrangement a highly polished pointer is used and it is sharply defined by its contrast with the black diaphragm 3B of the speaker I8.

In Figure 5, in which another arrangement of dial pointer and drive are shown, many parts are similar to those shown in Figures 1 to 4, inclusive, and like reference characters are applied thereto.

In stringing the cord belt 28 through the speaker diaphragm 36 as shown in Figure 4, the grommet 46 must have an exceptionally long slot therein if the speaker diaphragm is one of great excursion. To eliminate this type of grommet an arrangement shown in Figure 5 is employed wherein the cord belt 28 is brought through the speaker diaphragm 36 on a line substantially parallel to the axis of the cone 36. With this arrangement, the excursions of the diaphragm 36 are parallel to the cord belt 28 and the clearance between the grommet and cord belt is easily maintained.

In this figure, a dial pointer 46 has a blade formed similar to that of pointer 4| in Figure 4 and is mounted in a manner similar to pointer I3 on the grooved pulley I4. A second grooved pulley 41 havin a wide flange but similar in size to pulley I4 is fixed upon the rotatable shaft 20 of the variable condenser 2|. The cord belt 28 furnishes a connecting drive between grooved dial pulley I4 and the grooved pulley 41. A pair of grommets 48 are provided at the points where upper and lower reaches of the cord belt 28 pass through the diaphragm 36 of speaker I8. In

order to bring the cord belt 28 through these grommets on a line that is substantially parallel with the axis of the cone or diaphragm 36, the cord belt 28 performs a change in direction by bearing against a pair of idler pulleys 49 rotatably mounted on suitable projections (not shown) from the support bracket I5.

It is necessary, with this arrangement, to relocate the variable condenser 2| so its pulley 41 lines up with the upper and lower reaches of cord belt 28 as they emerge from the pair of grommets 48 in diaphragm 36. In re-locating the variable condenser 2| on the chassis 22, the relationship between shaft 20 of the variable condenser 2| and the manually operated shaft is altered.

The cord belt 26, when used in the arrange-- ment shown in Figure 3, provides the connecting drive between grooved pulley l9 and the tuning shaft 25 While traveling in a circuit outside the chassis 22. In the arrangement shown in Figure it is necessary for the cord belt 26 to pass through a pair of clearance holes 50 in the chassis 22 in order to furnish the connecting drive with the tuning shaft 5|. The tuning shaft 5| is provided with an annular groove 52 which is in tractive alignment with the grooved pulley 41.

Although with this arrangement there is shown some horizontal misalignment between the grooved pulley 41 and the tuning shaft 5|, the wide, smooth and rounded shoulder formed as an integral part of the grooved pulley 41 provides passage for the cord into the center grooved part thereof.

cased with other apparatus, such as, for example, radio-talking machine combinations and radio-television receiving sets.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

We claim:

1. A combined dial-speaker arrangement for a radio receiver comprising: a cabinet of a given height having a vertical panel of said height provided with a speaker aperture; a cone speaker having an acoustical driving system at the small end, having a large end with a vertical dimension approximately equal to said panel height,

and positioned Within said cabinet with said large end surrounding said panel aperture; a member, having a configuration corresponding to that of said large end of said speaker, positioned between and in engagement with said large end and said panel; at least one transparent and arcuate louver supported from said panel within said aperture and inclined to the plane of said aperture; a dial scale on said louver; a dial pointer supported for rotation about an axis lying within the envelope of said speaker and movable along said scale to indicate the tuning condition of said receiver; an adjustable element positioned to one side of said speaker for tuning said receiver;

and a mechanical driving system coupling said pointer to said tuning element and including a portion positioned in the vicinity of said large end of said speaker in a plane approximately normal to the axis of said speaker.

2. A combined dial-speaker arrangement for a radio receiver comprising: a cabinet of a given height having a vertical panel of said height provided with a speaker aperture; a cone speaker having an acoustical driving system at the small end, having a large end with a vertical dimension approximately equal to said panel height, and positioned within said cabinet with said large end surrounding said panel aperture; a member, having a configuration corresponding to that of said large end of said speaker, positioned between and in engagement with said large end and said panel; an exposed dial scale of arcuate configuration supported from said panel in the vicinity of said large end of said speaker; a dial pointer supported for rotation about an aXis lying within the envelope of said speaker and movable over said scale to indicate the tuning condition of said receiver; an adjustable element positioned to one side of said speaker for tuning said receiver; and a mechanical driving system coupling said pointer to said tuning element and including a portion positioned in the vicinity of said large end of said speaker in a plane approximately normal to the axis of said. speaker.

KURT EMDE. HERBERT H. STEGLICI-I.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,242,750 Jacobus May 20, 1941 2,272,660 Emde Feb. 10, 1942 FOREIGN PATENTS Number Country Date 471,733 GreatBritain Sept. 6, 1937 

